Field of the Invention
This invention relates to a wire saw.
Discussion of the Background
Wire saws, such as are commonly used to cut concrete, stone, marble and the like, have a flexible rope on which numerous abrasive beads are mounted in regularly spaced relationship. The beads may, for instance, have diamond particles exposed at their peripheries to perform the necessary cutting action. The rope is formed into an endless loop and is driven at a high linear speed against the workpiece which is to be cut.
When the wire saw is cutting, say laterally, through a workpiece such as a lump of stone, the abrasive beads are subjected to vertical and horizontal forces transverse to the rope and also to longitudinal forces acting along the rope. Random shock fluctuations in these forces can take place as the abrasive beads encounter relatively harder inclusions in the workpiece. The shock loading on the abrasive beads can damage the beads, particularly if the beads are rigidly fixed to the rope, for instance by brazing.
In addition to the transverse and longitudinal forces, the abrasive beads are also subjected to rotational forces as a result of the tendency of the rope to rotate. If the beads are freely rotatable on the rope, as opposed to being rigidly fixed, they are prone to rapid wear as a result of vibrations. Also, a freely rotatable bead will tend at an early stage to develop a flat wear area which then presents itself continuously to the workpiece, resulting in rapid wear in a localized area of the bead surface.